Conclusion In summary, all successful jumps (all jump types and rotation types) land with similar tibial shock, and for a given skater, the jump height is the same between single, doubles and triples. Skaters with greater proficiency had significantly greater jump height in their double jumps than less proficient skaters, yet the tibial shock at landing between the two groups was not significantly different. Skaters who can bend the ankle more during landing have significantly lower tibial shock at landing. The tibial shock at heelstrike when landing a jump on the ice is about tenfold greater than when running in sneakers. This dramatic difference between running and skating is largely related to the biomechanical limitations of the foot in the skate, suggest that a differently engineered skate is a needed to reduce the impact and shock of the landing. In addition, ankle strength training specific to shock absorption would further benefit the skater. Contact Kat: 267-476-2000, kat@icedynamics.net, www.icedynamics.net 1. Pecina, M., I. Bojanic, and S. Dubravcic, Stress fractures in figure skaters. Am J Sports Med, 1990. 18(3): p. 277-9. 2. Dubravcic-Simunjak, S., et al., The incidence of injuries in elite junior figure skaters. Am J Sports Med, 2003. 31(4): p. 511-7. 3. Fortin, J.D. and D. Roberts, Competitive figure skating injuries. Pain Physician, 2003. 6(3): p. 313-8. 4. Porter, E.B., et al., Sport-specific injuries and medical problems of figure skaters. WMJ, 2007. 106(6): p. 330-4. 5. Bruening, D.A. and J.G. Richards, The effects of articulated figure skates on jump landing forces. Journal of Applied Biomechanics, 2006. 22(4): p. 285-295.
16
MARCH | APRIL 2012
6. Lockwood, K.L. and P.J. Gervais, Impact forces upon landing single, double, and triple revolution jumps in figure skaters, 1997, University of Alberta. 7. Smith, A.D., The young skater. Clin Sports Med, 2000. 19(4): p. 741-55. 8. Milner, C.E., J. Hamill, and I. Davis, Are knee mechanics during early stance related to tibial stress fracture in runners? Clin Biomech (Bristol, Avon), 2007. 22(6): p. 697-703. 9. Voloshin, A.S., et al., Dynamic loading on the human musculoskeletal system -- effect of fatigue. Clin Biomech (Bristol, Avon), 1998. 13(7): p. 515-520. 10. Hreljac, A., Impact and overuse injuries in runners. Med Sci Sports Exerc, 2004. 36(5): p. 845-9. 11. Zifchock, R.A., I. Davis, and J. Hamill, Kinetic asymmetry in female runners with and without retrospective tibial stress fractures. Journal of Biomechanics, 2006. 39(15): p. 2792-2797.
Landing impact forces will be the topic of several presentations at the 2012 PSA International Conference & Trade Show in Boston May 24-26, 2012 where Mahlon Bradley M.D., Kat Arbour, Ph.D, Jim Richards, Ph.D, and Christy Krall will comprehensively address this focus. Registration for the 2012 PSA Conference & Trade Show is open now at www.skatepsa.com.